<html><head><base href="x-msg://250/"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi Paul, <div><br></div><div>I looked at the Helix and stenosis example but they are using cosine functions to deform </div><div><br></div><div>I tried to use a tangent function but it bends the whole pipe. </div><div><br></div><div>I dint look at peris example .</div><div><br></div><div>I will take a look at it and let you know.</div><div><br></div><div>Thank you </div><div><br></div><div>Kamal</div><div><br><div><div>On Jan 18, 2014, at 7:22 PM, <a href="mailto:nek5000-users@lists.mcs.anl.gov">nek5000-users@lists.mcs.anl.gov</a> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="direction: ltr; font-family: Tahoma; color: rgb(0, 0, 0); font-size: 10pt; "><br class="Apple-interchange-newline">Kamal,<div><br></div><div>Have you looked at the peris example? The usr file there shows how to deform</div><div>a pipe geometry.</div><div><br></div><div>Paul</div><div><br><div style="font-family: 'Times New Roman'; color: rgb(0, 0, 0); font-size: 16px; "><hr tabindex="-1"><div id="divRpF449769" style="direction: ltr; "><font face="Tahoma" size="2" color="#000000"><b>From:</b><span class="Apple-converted-space"> </span><a href="mailto:nek5000-users-bounces@lists.mcs.anl.gov">nek5000-users-bounces@lists.mcs.anl.gov</a> [<a href="mailto:nek5000-users-bounces@lists.mcs.anl.gov">nek5000-users-bounces@lists.mcs.anl.gov</a>] on behalf of <a href="mailto:nek5000-users@lists.mcs.anl.gov">nek5000-users@lists.mcs.anl.gov</a> [<a href="mailto:nek5000-users@lists.mcs.anl.gov">nek5000-users@lists.mcs.anl.gov</a>]<br><b>Sent:</b><span class="Apple-converted-space"> </span>Saturday, January 18, 2014 12:17 PM<br><b>To:</b><span class="Apple-converted-space"> </span><a href="mailto:nek5000-users@lists.mcs.anl.gov">nek5000-users@lists.mcs.anl.gov</a><br><b>Subject:</b><span class="Apple-converted-space"> </span>Re: [Nek5000-users] Pipe with expansion<br></font><br></div><div></div><div>Dear Paul, <div><br></div><div>I tried many ways to map my straight pipe geometry but it does not seem to work properly </div><div><br></div><div>I used something like </div><div><br></div><div>X = X + Z * tan ( alpha ) </div><div>Y = Y + Z* tan (alpha ) </div><div><br></div><div><br></div><div>even that dint work. could please help me with this </div><div><br></div><div>Thank you </div><div><br></div><div>Kamal.</div><div><br><div><div>On Jan 17, 2014, at 2:24 PM,<span class="Apple-converted-space"> </span><a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a><span class="Apple-converted-space"> </span>wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div bgcolor="#FFFFFF">Hi Paul,<span class="Apple-converted-space"> </span><br><br>Thanks paul. I tried working with the diverging mesh modification.<br><br>I tried to use this form of equation to modify the mesh<span class="Apple-converted-space"> </span><br><br>z = mx + b<br>z = ny + c<span class="Apple-converted-space"> </span><br><br>x = ( z - b ) / m<span class="Apple-converted-space"> </span><br>y = (z - c) / n<br><br>Do you think would work ? or is there any other way to input that ?<br><br>Thanks,<span class="Apple-converted-space"> </span><br><br>Kamal<br><br><br><div class="moz-cite-prefix">On 17/01/2014 14:14,<span class="Apple-converted-space"> </span><a class="moz-txt-link-abbreviated" href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a>wrote:<br></div><blockquote type="cite"><div dir="ltr">Kamal,<div><br></div><div>1) To check for convergence, run your simulation for increasing polynomial orders ( lx1 in the SIZE file) and measure some consistent quantity (drag, TKE, etc). You can plot this quantity against lx1 and this should give you a good picture of how you are converging (without needing to change the physical mesh).</div><div><br></div><div>2) If you weren't using temperature in your simulation, you could do put the following code snippet in your userchk</div><div><br></div><div>c-------------------------------------------</div><div>integer i, ntot</div><div><br></div><div>ntot = nx1*ny1*nz1*nelv ! total number of points in simulation (on THIS processor)</div><div><br></div><div>do i = 1,ntot</div><div> t(i,1,1,1,1) = 0.5*(vx(i,1,1,1)**2 + vy(i,1,1,1)**2 + vz(i,1,1,1)**2)</div><div>enddo</div><div><br></div><div>ifto = .true.</div><div>c-------------------------------------------</div><div><br></div><div>I've assumed here that your density is unity. This computed kinetic energy point-wise and stores it in the temperature field. The part "ifto = .true." tells Nek to output the temperature field whenever it outputs a field file. You could then view this in visit just like you would the velocity field.</div><div><br></div><div>Hope this helps!</div><div><br></div><div>Josh</div><div><br></div><div><br></div><div><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, Jan 15, 2014 at 9:52 AM,<span class="Apple-converted-space"> </span><span dir="ltr"><<a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a>></span><span class="Apple-converted-space"> </span>wrote:<br><blockquote class="gmail_quote" style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0.8ex; border-left-width: 1px; border-left-color: rgb(204, 204, 204); border-left-style: solid; padding-left: 1ex; ">Hi Paul,<br><br>I will try that mapping, I created a straight pipe to do some simulations.<br><br>1) Is there a way to check my spectral convergence, so that I can do some mesh convergence study?<br>2) Is there a way to plot the kinetic energy in the flow ?<br><br>Thank you,<br>Kamal<div class="HOEnZb"><div class="h5"><br><br><br><br>On 15/01/2014 12:14,<span class="Apple-converted-space"> </span><a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a><span class="Apple-converted-space"> </span>wrote:<br><blockquote class="gmail_quote" style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0.8ex; border-left-width: 1px; border-left-color: rgb(204, 204, 204); border-left-style: solid; padding-left: 1ex; "><br>Hi Kamal,<br><br>For the geometry you describe, I would apply mesh morphing<br>to a standard straight pipe. You can create such a pipe<br>using a subset of the mkmesh script provided in the expansion<br>example.<br><br>If your transition region is conical, then I woud make<br>certain that the change in slope occurs at element boundaries,<br>i.e., as in the half cross-section depicted below:<br><br> _______________<br> /| | |<br> / | | |<br> /| | | |<br> ________________/ | | | |<br> | | | | | | | |<br> | | | | | | | |<br> +-----+-----+---+--+---+------+------+----> z<br><br><br>Paul<br><br><br><br>On Wed, 15 Jan 2014,<span class="Apple-converted-space"> </span><a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a><span class="Apple-converted-space"> </span>wrote:<br><br><blockquote class="gmail_quote" style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0.8ex; border-left-width: 1px; border-left-color: rgb(204, 204, 204); border-left-style: solid; padding-left: 1ex; ">Hi Paul,<br><br>I looked at the example and it looks very helpful, but for a sudden expansion we have only two parts (i.e) the inlet pipe and the outlet pipe. Whereas in a diverging pipe we have three section (i.e,) The inlet pipe, Diverging section and the outlet pipe.<br><br><br>Is it possible for me to create a 2D diverging section using mesh modification and revolve it around the centre axis to get a 3d diverging pipe ?<br><br><br>or should I apply the mesh modification directly to the 3d sudden expansion pipe using usrdat2() ?<br><br>Thanks,<br>Kamal<br><br><br>On 14/01/2014 21:09,<span class="Apple-converted-space"> </span><a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a><span class="Apple-converted-space"> </span>wrote:<br><blockquote class="gmail_quote" style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0.8ex; border-left-width: 1px; border-left-color: rgb(204, 204, 204); border-left-style: solid; padding-left: 1ex; ">Hi Paul,<br><br>Thanks a lot for the update. I will take a look at as soon as possible and keep you updated with it.<br><br>Thank you,<br><br>Kamal<br><br>On Jan 14, 2014, at 9:04 PM,<span class="Apple-converted-space"> </span><a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a><span class="Apple-converted-space"> </span>wrote:<br><br><blockquote class="gmail_quote" style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0.8ex; border-left-width: 1px; border-left-color: rgb(204, 204, 204); border-left-style: solid; padding-left: 1ex; ">Kamal,<br><br>I've added an example for a step-type expansion in a pipe. New example directory<br>is nek5_svn/examples/expansion, with a README.<br><br>If you want a standard diffuser, I would use mesh-morphing, as outlined in the<br>nek primer, which can be found on this page:<br><br><a href="http://nek5000.mcs.anl.gov/index.php/UG#Documentation" target="_blank">http://nek5000.mcs.anl.gov/index.php/UG#Documentation</a><br><br>I've also automated our turbulent outflow bc treatment -- one simply provides an<br>expansion factor (typically ~ 1.5) and two persistent arrays to turb_outflow(), which<br>is now in navier5.f. This can be useful when very strong vortices are leaving the<br>domain, which is possible for certain diffuser flow conditions (and others).<br><br>Paul<br>________________________________________<br>From:<span class="Apple-converted-space"> </span><a href="mailto:nek5000-users-bounces@lists.mcs.anl.gov" target="_blank">nek5000-users-bounces@lists.mcs.anl.gov</a><span class="Apple-converted-space"> </span>[<a href="mailto:nek5000-users-bounces@lists.mcs.anl.gov" target="_blank">nek5000-users-bounces@lists.mcs.anl.gov</a>] on behalf of<a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a><span class="Apple-converted-space"> </span>[<a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a>]<br>Sent: Monday, January 13, 2014 3:35 AM<br>To:<span class="Apple-converted-space"> </span><a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a><br>Subject: [Nek5000-users] Creating a Mesh<br><br>Hi<br><br>Can some one please help me in this because I am new to nek<br><br>1) How can I create a .rea for a specific geometry say ' A sudden<br>expansion pipe ' or a ' Diverging pipe '<br><br>2) What tool I should use to create that mesh.<br><br><br>Thank you<br><br><br>kamal<br>_______________________________________________<br>Nek5000-users mailing list<br><a href="mailto:Nek5000-users@lists.mcs.anl.gov" target="_blank">Nek5000-users@lists.mcs.anl.gov</a><br><a href="https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users" target="_blank">https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users</a><br>_______________________________________________<br>Nek5000-users mailing list<br><a href="mailto:Nek5000-users@lists.mcs.anl.gov" target="_blank">Nek5000-users@lists.mcs.anl.gov</a><br><a href="https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users" target="_blank">https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users</a><br></blockquote>_______________________________________________<br>Nek5000-users mailing list<br><a href="mailto:Nek5000-users@lists.mcs.anl.gov" target="_blank">Nek5000-users@lists.mcs.anl.gov</a><br><a href="https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users" target="_blank">https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users</a><br></blockquote><br>_______________________________________________<br>Nek5000-users mailing list<br><a href="mailto:Nek5000-users@lists.mcs.anl.gov" target="_blank">Nek5000-users@lists.mcs.anl.gov</a><br><a href="https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users" target="_blank">https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users</a><br><br></blockquote>_______________________________________________<br>Nek5000-users mailing list<br><a href="mailto:Nek5000-users@lists.mcs.anl.gov" target="_blank">Nek5000-users@lists.mcs.anl.gov</a><br><a href="https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users" target="_blank">https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users</a><br></blockquote><br>_______________________________________________<br>Nek5000-users mailing list<br><a href="mailto:Nek5000-users@lists.mcs.anl.gov" target="_blank">Nek5000-users@lists.mcs.anl.gov</a><br><a href="https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users" target="_blank">https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users</a><br></div></div></blockquote></div><br><br clear="all"><div><br></div>--<span class="Apple-converted-space"> </span><br>Josh Camp<br><br>"All that is necessary for the triumph of evil is that good men do nothing" -- Edmund Burke </div><br><fieldset class="mimeAttachmentHeader" target="_blank"></fieldset><br><pre>_______________________________________________
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